from random import choice

class RandomWalk():
    def __init__(self,num_points=5000):
        self.num_points = num_points
        #所以随机数都始于0
        self.x_values = [0]
        self.y_values = [0]

    def fill_walk(self):
        while len(self.x_values) < self.num_points:
            #决定前进方向以及沿着这个方向前进的距离
            x_direction = choice([1,-1])
            x_distance = choice([0,1,2,3,4])
            x_step = x_direction * x_distance

            y_direction = choice([1,-1])
            y_distance = choice([0,1,2,3,4])
            y_step = y_direction * y_distance

            #拒绝原地踏步
            if x_step == 0 and y_step == 0:
                continue
            #计算下一个点的x和y
            next_x = self.x_values[-1] + x_step
            next_y = self.y_values[-1] + y_step
            #将下一步的值存储到数组
            self.x_values.append(next_x)
            self.y_values.append(next_y)